Yes. It certainly will. The "Free International Calling" feature depends only on where you are calling, not
where you are calling from.
However, because Tello does not offer "roaming" just yet, you will need to avail yourself of 1 of the following 2 options while abroad.
1. Wi-Fi Calling & Text
This is a feature available on the vast majority of Tello GSM-compatible phones and you can check your phone settings to confirm.
It allows for calling & texting (sending & receiving) via the closest available Wi-Fi network which could be at a hotel, your office, at home, or even a Wi-Fi hotspot.
If you have set up Wi-Fi Calling correctly, it does not use up data from your Tello data plan, it just uses minutes from your calling plan as normal as long as the destination you are calling is included in our 60+ countries list.
See full details on this blog
2. "My Tello" App
You also have the option of using our free "My Tello" app to make calls through Wi-Fi.
You cannot RECEIVE calls via the App and texting is also NOT available via the App - it is only to make calls.
The "My Tello" app is free to download for iOS and Android users.
To make a call, simply dial the destination number from the keypad (always include country code) or choose from your phone "Contacts" tab (ensure the number is in international format).